Added note about `.logical_width()` being the primary calculation point that all other sizing is based off of.
Added note about `.logical_width()` being the primary calculation point that all other sizing is based off of.

alanwsmith/doc-write-image-loader,alanwsmith/doc-write-image-loader,alanwsmith/document.write-image-loader,alanwsmith/doc-write-image-loader,alanwsmith/document.write-image-loader